Coated article



March 12, 1946.

J. J. BROP-HY 2,396,313.

COATED ARTICLE Original Filed July 29, 1940 Fjgl 1. 5/

67 I'fl "/2 Q 9/ 89 5 6/ if 7 75 1 5/ 4/ 69 2/ Patented Mar. 12, 1946 COATED ARTICLE John J. Brophy, Salem, Mass., assignor to United Shoe Machinery Corporation, Flemington, N. 1.,

a corporation of New Jersey Original application July 29, 1940, Serial No. 348,096. Divided and this application June 15, 1942, Serial No. 447,116

4 Claims.

This invention relates to temporary protective covers which, after having served their purpose, may be readily removed, and is herein set forth as a covered article such as a shoe or shoe part.

In the manufacture of shoes the display surfaces of certain parts, such for example as those which make up the upper and commonly consist of leather and/or fabric, are subjected to con siderable handling and to contact with parts of machines during various shoemaking operations, whereby the uppers, are liable to be stained and soiled. Temporary protective covers of two general types have been proposed and used to some extent, namely, preformed covers such, for example, as those made of paper, and covers in the form of coatings, such as those made in situ, for example, by spraying a coating of a substance, such as rubber latex, upon the uppers. The general object of the present invention is to provide a novel and improved cover or coating of the latter type.

To this end, a procedure may be used which comprises providing a colloidal solution of a vinyl resin and spraying the solution upon an article, the solution being a nearly saturated one at the spraying temperature, the particles of the spray' a temporary protective cover or coating which adheres lightly to the article and may readily be peeled off when it has served its purpose.

Referring to the accompanying drawing,

Fig. l is an elevation of an apparatus by the use of which the method of the present invention may be practiced;

Fig. 2 is a fragment of a portion of a shoe upper over which the spray has passed once. In this figure the filaments of the spray have been greatly enlarged; and

Fig, 3 is an elevation of a lasted shoe, to the upper of which a protective coating has been applied. I

The illustrated apparatus, which is designed particularly for use on a lasted shoe, comprises a generally rectangular compartment 5 open at one side in which the spraying is done. A support I for a lasted shoe I00, which is to be coated, 1s

pivotally carried by a bracket fl-which is fast to or integral with a wall of the compartment 5, said support being so constructed that the shoe may be swung andturned in various paths so as to permit all localities on the upper of the shoe to be exposed to a spray which emerges from a spray gun, the nozzle of which appears at H and the trigger at I3. The gun may be heated, if desired, by an electric heater to which current is supplied through a cable l4; and the heating element as well as the greater part of the gun is covered by heat insulating material I5 to permit the gun to be readily handled. As shown, the gun, which is not being used, is hung on a hook, not shown, carried by a wall of the compartment 5. In coating the upper of a shoe the operator holds the spray gun in one hand, while with the other he manipulates the support I by means of a handle I1 and causes the spray to travel over the upper. Depending upon the nature of the material of which the spray is formed and the nature of the upper of the shoe, the spray may be caused, if desired, to travel a plurality of times over the upper so as to build up a coating.

Leading into the spray gun.are two flexible pipes i9 and 2| which conduct respectively the colloidal spray material or compound and the compressed air. Current is supplied to a heating element which surrounds the pipe I9 through a cable 25, this pipe and its heating element, as Well as the pipe 2|, being covered by heat-insulating material. A rheostat, not shown, provides means for controlling the temperature of the pipe l9.

There are provided two pots 3|, 33 for the resinous material, either of which may be put into communication with the pipe H to supply heated material to the spray gun. To this end the outlet 35 of the pot 3| and the outlet 31 of the pct 33 are connected to a valve casing 39, which is also connected through a T 4| and various pieces of piping with the lower end of the flexible pipe l9. In the casing 39 is a valve which may be turned by means of a handle 43 to put either pot into communication with the pipe IE! or to shut all communication with either pot. Fast to or integral with the bottom of the pot 3| is an electrical heater 32, and a similar heater 34 is provided for the pct 33, current being supplied through a cable 36 and governedrespectively by thermostats 23 and 21,

The compressed air, which is forced unheated into the upper portion of the selected pot 3 or 33 as well as that which is heated and supplied through the pipe 2| to the spray gun, enters from a source of supply through a pipe 45. After passing through an air purifier 41, it divides and to the top of the selected pot 3| or 33. In the operation of the apparatus the air is ordinarily supplied to the spray gun at a pressure of 60 pounds per square inch and to the top oi! the selected pot at 50 pounds per square inch. The air, which passes through the pressure gage 5|, passes through a safety valve 53 and thence through a rigid pipe 55 and a flexible pipe 61 to one branch of a T 59. The upper branch of the T 59 is connected through piping to a T 62, the two horizontal branches of which are in alinement, being connected respectively to the inlet of a valve iii and to the inlet of a valve 63. The outlet of the valve 6| is connected to one of the horizontal branches of another T 66, the vertical branch of which'is connected to piping which leads into the top of the pct Si. The other horizontal branch of the T 65 is connected to one of the horizontal branches of a third T 61, the vertical branch of which is connected to a small exhaust pipe 69. In the T 61 is a spring-pressed valve, not shown, which normally cuts off communication between the T 61 and the small exhaust pipe 69. This valve is provided with a stem having a head 'H, the construction being such that pushing in the stem puts the space in the top of the pot 3i into communication with the exhaust pipe 69. One branch of the T 63 is similarly connected by piping to the top of the interior of the pct 33, and at the right hand end of this piping is a T I3, fitted, as is the T 61, with a spring-pressed relief valve having a head, not shown. like the head H and operating in the same manner as the head H. The exhaust pipe 69 near its" middle is connected by a fitting to a flexible pipe, not shown, which leads up into the spray compartment. At the end of the day's work it is desirable to release the pressure upon the material in the pots and also to blow out of the pipe l9 and the spray gun the resinous material which they contain. At such times the valve 43 is turned to shut ofl connection from both pots to the pipe I9; the valves 6i and 63 are closed to out 01f the flow of air to the tops of the pots; and the head of the relief valve in the T 61, as well as that of the corresponding relief valve in the T 13, is pushed in to relieve the pressure in the pots. In order to blow the material out of the pipe l9 and the spray gun, a valve Ti, which has hitherto been closed, is

opened to cause compressed air to flow from the pipe 51, through the valve 11, thence through a small pipe 19 into the T 41. From here it flows on through the flexible pipe i9 and the spray gun so as to force all the resinous spraying material out of the pipe and the gun.

The compressed air for the spray gun, after passing through the pressure gage 49, passes through piping 81 which leads down below the floor of the compartment 5, and through a valve having a handle 95. From this valve the air passes through a heater 89 and into the pipe 2|, there being provided a thermometer 99 which registers the temperature of the air. From the valve, the handle of which is shown at 95, a

pipe 91 leads directly into the pipe 2| so that unheated air may be passed through the spray gun if desired by properly turning the handle.

In the operation of the apparatus, regardless of the composition of the resinous material which is used, the pressure of air in the top of the pot is ordinarily about 50 pounds per square inch, and the pressure or air delivered to the spray gun is about 60 pounds per square inch; but the temperature oi the material and the temperature of the compressed air delivered to the gun vary considerably according to the nature of the material.- This material is maintained as an easy flowing liquid by the heat applied to the pot which is being used and to the pipe i9. It is further heated and thinned by the heated air from the pipe 2!; and, ii the heater for the spray gun is being operated, a further heating of the air and thinning of the resinous material takes place. The apparatus which has been thus briefly disclosed forms no part of the present invention, and any suitable apparatus may be employed.

Examples oi resinous materials which may be used are given below.

Vinylite XYSG, a product of the Carbide 8: Carbon Chemicals Corporation of New York, is a vinyl acetal which results from the interaction of polyvinyl alcohol and butyraldehyde. Plasticizer 3GH (triethylene glycol di-Z-ethylbutyrate), a product of the same corporation, is a plasticizer particularly adapted for use with the socalled X resins, of which Vinylite XYSG is one. The ingredients are mixed for 75 to hours, the product being a viscous liquid. Alcohol is a solvent for the resin. Acetone is not a solvent at room temperature. It has a much lower boiling point than the alcohol and increases the evaporation of the alcohol during the spraying of the material. In use, this material is maintained as an easy flowing liquid at about 100 F. in the pot and in the pipe l9; and the temperature of the air blast is about F., the gun itself not necesarily being heated other than by the blast of hot air. This air, as is usual in spray guns, flows around the small amount of spray material which is flowing through the gun until the air and the spray material meet; and, since the air is at a much higher temperature than the spray material, it further heats this material and thins it so that it is broken up into a spray of fine particles.

What takes place during the coating of the shoe is believed to be as follows. When the material is broken up into a fine spray, its surface area is greatly increased. The particles of the spray at their point of formation are sticky but are caused to decrease in stickiness, by loss of solvent as they travel from their point of formation and by being cooled as they are deposited upon the shoe; the particles, when they are deposited upon the shoe, being much drier as well as at a much lower temperature than when they left the gun. The principal function of the acetone in this example, as has been stated, is to increase the amount of alcohol which is driven ofi by the hot air. It is believed that most of the acetone and the greater part of the alcohol are thus removed. In any event, the particles as they are deposited upon the shoe adhere lightly to the shoe and vfirmly to each other so as to form a tough flexible coating which shrinks slightly upon standing and can readily be peeled from the upper of the shoe when it has served its purpose.

Example 11 p Parts by weight Vinylite XYSG 156 Plasticizer 3GH 78 Durez resin #550 78 Acetone 981.5

Durez resin #550, a'phenol formaldehyde resin in the A stage, is a product of Durez Plastics and Chemical Inc. of North Tonawanda, New York. It is compatible with .the vinyl resin, aids in producing a sprayof fine particles, and probably increases the stickiness of the coating. Acetoneis a solvent for the vinyl resin only at elevated temperatures. The ingredients may be put together as follows: The Durez resin is dissolved in the acetone; and into this solution is stirred first the plasticizer and then the vinyl resin. The ingredients are placed in a closed than by the blast of air. This hot air, as has been explained above, further heats and thins the spray material, which is flowing through the gun, and breaks it up into a fine spray. What takes place during the coating of the shoe is similar to what has been described in connection with Example I, but is somewhat different due to the fact that the only liquid present is the volatile acetone. When the material is broken up into a fine spray, its surface area-is greatly increased. The sticky particles are caused to decrease in stickiness by loss of solvent during their travel and by being cooled as they are deposited upon the shoe at which time most of the acetone has been removed. In any event, they form upon the shoe a tough flexible coating which adheres lightly to the shoe and can subsequently be readily peeled off.

Example III Parts by weight Vinylite I XYSG 156 Plasticizer 3GH 78 Durez resin #550 '78 Acetone 981.5 Nokorode 6.5

The Nokorode, by which this formula difiers from the preceding one and which acts to cause the final product to be somewhat thinner, consists substantially of--,

. Parts by weight Petrolatum 65.9 Zinc chloride 22.7 Ammonium chloride 2.9 Water 7.6

(2) The Nokorode isstirred into the rest of the acetone which has been heated to its boiling point.

ride, disperses readily in the hot acetone.

(3) The Nokorode dispersion is poured into the Durez resin solution.

(4) The plasticizer is stirred in.

(5) The Vinylite XYSG is stirred in and the resulting product allowed to stand for 24 hours.

(6) The resulting compound ispacked in ,a drum and heated at from 176 F. to180 F. for 18 hours. The product, when cooled to room temperature, is a very viscous liquid, which, like the compound of Example II, becomes a thin liquid when sufficiently heated.

The coating produced by using the compound of Example III is a little more sticky than that produced by using the compound of Example I, and its exposed surface may be dusted, if desired, with some substance, such as powdered tale, to reduce its stickiness. Substantially the same temperatures of compound and air blast are maintained with the compound as with the compound of Example II.

When a protective coating is applied to a lasted shoe, a part of the coating extends over upon the margin of the bottom of the shoe, and

this part helps maintain the coating in place.

In a McKay shoe or a Goodyear welt shoe it is not necessary to disturb this part, but in a shoe, the sole of which is to be attached by cement,

. it is necessary to remove this part preparatory to or during the roughing of the margin of the bottom of the shoe. shoes to which soles are attached by cement, it is desirable that the coating should adhere slightly more firmly than when shoes of the McKay or Goodyear welt type are being manufactured. The compound of Example III is well suited for use in the manufacture of all types of shoes and particularly shoes the soles of which are at-" tached bycement.

In the examples given above the solutions used for spraying are nearly saturated solutions at the temperature at which the spray is formed, the temperature of the material and that of the compressed air delivered to the spray gun varying considerably according to the nature of thespray material and the wetness desired in the coating as first formed, that is, the time it will take for the coating, as first formed, to dry out to a hard,

tough condition. The particles of spray at their pointof formation contain just about sufiicient solvent to dissolve their solid content; but, as these particles travel from the gun to the article, enough solvent is evaporated so that the particles gel to form as they strike the article, a lightly adherent coating.

V Example IV Vinylite XYSG 1 parts by weight Plasticizer 3GH 1 /2 parts by weight Durez resin #550 1 parts by weight Calcium stearate 2% of total weight The calcium stearate is a heat stabilizer, its

.function being to counteract the tendency of the The petrolatum melts and, together with the zinc chloride and the ammonium chlo- Thus, in the manufacture of ing to the spray gun are maintained at about 300 R, which keeps the resinous compound in the form of an easy-flowing liquid. The temperature of the air blast is about 400 F. and that of the spray gun is also about 400 F., the gun being thus heated to ensure that any loss in heat of the air while passing through the pipe 2! shall be made up. By this high heat the spray material is further thinned and, when it encounters the blast of hot air, it is broken up into a fine spray. It will be noted that the compound of this example contains no ingredient, such as acetone, which is liquid at room temperature. When a cover is formed in situ upon the upper of a shoe, for example, by spraying upon it a coating material in the form of a solution, the material as it coalesces upon the upper contains a certain amount of the liquid; and, with the many kinds and shades of colored leather which are used in making shoes, there is a possibility that some dye which has been used in coloring the leather may be attacked by the liquid. When a coating, which when applied contains a solvent for a dye, is subsequently peeled off after having served its purpose, a certain amount of the dye is liable to be removed with it, and the color of the leather, usually in spots, is dulled or otherwise objectionably aifected so that touching up the spots and/or recoloring the whole area in which the spots occur is necessary. With the compound of Example IV this tendency is greatly diminished.

At the time when the molten resinous compound is broken up into a spray, the particles of the spray being at an elevated temperature,

are very sticky, but, as they travel from the spray gun to the shoe, they are cooled considerably, and when they strike the shoe a further cooling occurs, the result being that they are at a suitable temperature to coalesce into a firm coating which adheres with just suflicient firmness to the shoe.

The shape of the particles of the spray may be varied, for example by varying the pressure of the air or by varying the viscosity of the spray material. Particles in the form of minute filaments have been found to be satisfactory, and particularly so in certain instances, for example when the uppers of the shoes are made of linen heavily loaded with a stiffening substance. Fig. 2 shows a fragment of a part of an upper over which a spray of filaments has passed for the first time in the course of building up a coating, the particles being shown as greatly enlarged. The minute filaments, many of which have small heads or enlargements at one end,

the shoe.

are to an extent separate from one another, but to some extent they touch and cross one another. The succeeding applications of the spray to this locality progressively fill and/or cover the empty spaces by causing succeeding filaments to be deposited upon and at an angle to those already on There is thus formed first a reticulated coating and then a substantially continuous coating.

Since the covers are made of material which may be dissolved or melted, as may be desired, the scrap which results when the covers-have been removed from the shoes may be reclaimed or regenerated and used again.

For convenience, the invention has been illustrated and described with reference toapplying a temporary coating or cover to the upper of a lasted shoe. It should be understood, however, the coating may be applied to shoe parts in the fiat and to articles other than shoe parts, and that fillers and coloring matter may be incorporated in the compound if desired.

The present application is a division of application Serial No. 348,096, filed July 29, 1940.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

l. A shoe part having a single sprayed temporary protective coating comprising a vinyl resin and a plasticizer therefor formed in situ directly upon it, said coating adhering to the shoe part sufiiciently to remain in place while the shoe part is being subjected to various manufacturing operations but being capable of being readily peeled off after it has served its purpose.

2. An article having a single sprayed tem-, porary protective coating comprising a vinyl resin and a plasticizer therefor formed in situ directly upon it, said coating adhering lightly to the article and being capable of being readily peeled off after it has served its purpose.

3. An article having a sprayed temporary protective coating deposited from a solution of a vinyl resin and a plasticizer therefor, said coating adhering lightly to the article and being capable of being readily peeled off after it has served its purpose.

4. An article having a sprayed, temporary protective coating comprising a vinyl resin and a plasticizer therefor, said coating consisting of superposed filaments arranged at random and adhering lightly to the article but being capable of being readily peeled ofi after having served its purpose.

JOHN J. BROPHY. 

